diff --git a/src/CUDA/CudaBase.cu b/src/CUDA/CudaBase.cu
index 03fa327..b6af691 100644
--- a/src/CUDA/CudaBase.cu
+++ b/src/CUDA/CudaBase.cu
@@ -41,14 +41,15 @@ CudaBase::~CudaBase() {
 /*
   create curandStates
 */
-int CudaBase::cuda_createCurandStates(int size) {
+int CudaBase::cuda_createCurandStates(int size, int seed) {
 
   if (defaultRndSet == 1)
     cuda_deleteCurandStates();
 
   int threads = 128;
   int blocks = size / threads + 1;
-  int seed = time(NULL);
+  if (seed == -1)
+    seed = time(NULL);
 
   //std::cout << "sizeof: " << sizeof(curandState) << std::endl;
   cudaMalloc(&defaultRndState, sizeof(curandState)*size);
diff --git a/src/CUDA/CudaBase.cuh b/src/CUDA/CudaBase.cuh
index 325016d..6f3d182 100644
--- a/src/CUDA/CudaBase.cuh
+++ b/src/CUDA/CudaBase.cuh
@@ -41,7 +41,7 @@ public:
    * and create a curandState with different seed for each array entry.
    * Return success or error code
    */
-  int cuda_createCurandStates(int size);
+  int cuda_createCurandStates(int size, int seed = -1);
 
   /**
    * Delete curandState.
diff --git a/src/DKSBase.cpp b/src/DKSBase.cpp
index 96e9b19..8ea5f58 100644
--- a/src/DKSBase.cpp
+++ b/src/DKSBase.cpp
@@ -807,9 +807,9 @@ int DKSBase::callCollimatorPhysicsSortSoA(void *label_ptr, void *localID_ptr,
 }
 
 
-int DKSBase::callInitRandoms(int size) {
+int DKSBase::callInitRandoms(int size, int seed) {
   if (apiCuda()) 
-    return CUDA_SAFECALL(cbase->cuda_createCurandStates(size));
+    return CUDA_SAFECALL(cbase->cuda_createCurandStates(size, seed));
   else if (apiOpenCL())
     return OPENCL_SAFECALL(oclbase->ocl_createRndStates(size));
   else if (apiOpenMP())
diff --git a/src/DKSBase.h b/src/DKSBase.h
index ea8bc39..79e23c8 100644
--- a/src/DKSBase.h
+++ b/src/DKSBase.h
@@ -1074,7 +1074,7 @@ public:
    * Init random number states and save for reuse on device.
    * TODO: opencl and mic implementations.
    */
-  int callInitRandoms(int size);
+  int callInitRandoms(int size, int seed = -1);
 
   /**
    * Integration code from ParallelTTracker from OPAL.